Vaccuum advance problems

Vaccuum advance problems


Senior Jeeper
SW Pennsylvania
1977 cj7 Golden Eagle 304,automatic, Quadra-trac, full restoration just "finished." 4 inch superlift, lift shackles in the front, sitting on some KM2 Mud terrians
1999 tj 4 cylinder ax5 trans 3 inches lift 31s
1956 Dj3a all original except axles and engine, Hurricane 4 cyl. 4x4 conversion, 27,500 original miles 58 Jeep-A-Trench cj5 8000 miles.
my jeeps vacuum advance isnt working properly.... and the distributor is before 5 degrees TDC. but the vacuum advance is pointing up instead of down towardds the fan. i dont know why its giving me trouble.:confused: the vacuum advance may be bad or i have to turn it. would it help if i turned it? i have vacuum in the line its just not advancing properly. what might be the problem?

How are you testing the advance?
well i did plug two lines. i have come to the conclusion that the accelerator pump. it keeps bypassing.
What are you having trouble with?
i just try to feed gas easily and it seems like its not advancing. i have to pump it for it to advance. it feels like its pulling a load. i think its the accelerator pump bypassing i am not sure

Not really grasping what your asking.. your vacuum advance works of the vaccum created when the motor is is running. THe faster the motor is going the more vacuum is produced which inturns advances the timing. if your slowly trying to throttle up and advance the timing it might not be noticable.

the accelerator pump really has nothing to do with the vacuum advance. ot provides the motor with a squirt of gas to help keep up with the sudden demand when the throttle is opened quickly.

If you want to see if the vacuum advance is operating correctly get a vacuum tester OEM 25136 Vacuum Pump: Home Improvement

and pull a vacuum that way. If it pulls the lever it is good.. if it dosent advacne under the vacuum from the tester its no good. IF you get a good test with the tester but it doesnt work when its hooked up to the carb you have a vacuum leak or other issue.

Let me google that for you
in first gear it accellerates fine, in drive it just spits and sputters before it gets going. once i get the rpms up it runs great. i was thinking maybe the accelerator pump is bad. maybe bypassing gas thru the carb. i am not sure. but when i start out it seems like im pulling a heavy trailer.
So is your problem acceleration? The sputtering? The advance? Have you changed fuel filters? The sock in the tank? It sounds like your making a quick judgement on the vacuum advance and not looking at the rest of the stuff.

How bout you post exactly what the problem is and we can start giving optinions from there. Alot of time if you idle fine but accelerates like :dung: you can also have a fuel delivery problem like clogged line, filter, or tank sock. When you idle enough fuel sneaks by to keep it running fine but when you step on it it doesn't get enough flow and you get no power.
thats all it is. it idles and accelerates fine when NOT in drive. but when i put it in drive, it hesitates. i put a new fuel filter and lines on. i have done everything i could to the timing and the vacuum on the distributor. i just dont know what may be wrong.
so what happens when you start out in frist and shift it manually to 2nd and than drive?
in first it will do anything fine. i dont even use 2nd i just shift to drive. when i try to start in drive, it sputters, and acts like im pulling something behind me. ive had the carb rebuild and the fuel lines and fuel filters replaced. but it sputters and dogs. if i pump it it will sputter then run fine after that.
This has me :confused: does it seem to be starting out in 1st when you start in drive? can you fell it shift through all the gears? I've never heard of one starting in a higher gear in D but I guess anything is possable.
well here it is. when in park or neutral. i can rev it perfectly fine. in drive one; i can push the pedal to the floor and it wont load up or dog or anything. (i dont use drive 2) in Drive; i put the pedal to the floor. it spits and sputters, and i have to pump the gas to get it back up to the right RPMs then it takes off. in reverse; it does the same exact thing as in drive. i was maybe thinking accelerator pump. but when i posted this thread i thought i had vac problems, but right after i posted that i had vac problems, a friend of mine came and fixed the vac.

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